# ChatRail

> ChatRail is context-aware WhatsApp infrastructure for developers. It sends WhatsApp alerts, returns inbound replies and delivery updates through webhooks, and can optionally answer follow-up questions using data attached to the original alert.

ChatRail uses WhatsApp Linked Devices rather than Meta's official WhatsApp Business Platform. AI is optional. ChatRail is currently in early access.

## Product and documentation

- [Product overview](https://chatrail.dev/): Main product capabilities, interactive demo and FAQ.
- [Documentation](https://chatrail.dev/docs): Technical overview and guide index.
- [WhatsApp API](https://chatrail.dev/whatsapp-api): Authentication, sending, connection model and delivery states.
- [WhatsApp Linked Devices API](https://chatrail.dev/whatsapp-linked-devices-api): Pairing, connection state, trade-offs and recovery planning.
- [WhatsApp API without Meta approval](https://chatrail.dev/whatsapp-api-without-meta-approval): What the linked-device route does and does not mean.
- [WhatsApp API for an existing number](https://chatrail.dev/whatsapp-api-for-existing-number): Add API workflows while retaining an established number.
- [WhatsApp API pricing](https://chatrail.dev/whatsapp-api-pricing): Connections, message credits, optional AI usage and external costs.
- [WhatsApp webhook](https://chatrail.dev/whatsapp-webhook): Search-oriented guide to signed events, replay safety and fast acknowledgement.
- [Use ChatRail with n8n](https://chatrail.dev/integrations/n8n): HTTP Request and Webhook node implementation pattern.
- [Use ChatRail with Node.js](https://chatrail.dev/integrations/nodejs): Server-side sends, bounded retries and webhook verification.
- [Webhook integration](https://chatrail.dev/integrations/webhooks): Transport-neutral HTTPS event integration pattern.
- [Property-alert workflow](https://chatrail.dev/workflows/property-alerts): Event, interaction, reply path and operational outcome.
- [Order-update workflow](https://chatrail.dev/workflows/order-updates): Fulfillment alerts and controlled customer actions.
- [Monitoring-alert workflow](https://chatrail.dev/workflows/monitoring-alerts): Acknowledgements, escalation and fallback-channel planning.
- [Webhooks](https://chatrail.dev/webhooks): Inbound messages, delivery updates, signatures and idempotency.
- [Context-aware AI replies](https://chatrail.dev/context-aware-ai-replies): Optional answers grounded in alert data.
- [MCP server](https://chatrail.dev/mcp): Workspace operations available to compatible coding assistants.
- [Integrations](https://chatrail.dev/integrations): Application, automation and model connections.
- [Security](https://chatrail.dev/security): API, webhook, connection and data-handling controls.
- [Pricing](https://chatrail.dev/pricing): Current early-access plans and limits.
- [Tutorials](https://chatrail.dev/tutorials): Practical implementation guides.
- [Property alerts tutorial](https://chatrail.dev/tutorials/property-alerts): Send listing context and support relevant follow-up questions.
- [Order updates tutorial](https://chatrail.dev/tutorials/order-updates): Connect fulfillment events to contextual WhatsApp replies.
- [Weekend digests tutorial](https://chatrail.dev/tutorials/weekend-digests): Normalize, rank and deliver personalized event alerts.
- [Reliable webhook handler](https://chatrail.dev/tutorials/webhook-handler): Verify signatures and process events idempotently.
- [n8n WhatsApp workflow](https://chatrail.dev/tutorials/n8n-whatsapp-workflow): Connect n8n triggers and webhooks to ChatRail.
- [Privacy](https://chatrail.dev/privacy): Website and early-access privacy notice.
- [Terms](https://chatrail.dev/terms): Terms of use.
- [Acceptable use](https://chatrail.dev/acceptable-use): Platform restrictions.

## Key facts

- Audience: developers, technical operators and agencies building WhatsApp alerts and workflows.
- Core interface: JSON over HTTPS plus signed webhook events.
- AI: off by default and enabled per connection.
- Context: structured data may be attached to an alert and used for relevant follow-up replies.
- MCP: an operational interface for inspecting connections, delivery state, failures and schedules.
- Meta status: not affiliated with or endorsed by Meta or WhatsApp.

- [workflows — approval-requests](https://chatrail.dev/workflows/approval-requests): Practical implementation guide.
- [workflows — appointment-reminders](https://chatrail.dev/workflows/appointment-reminders): Practical implementation guide.
- [workflows — delivery-exceptions](https://chatrail.dev/workflows/delivery-exceptions): Practical implementation guide.
- [guides — reliable-whatsapp-message-queue](https://chatrail.dev/guides/reliable-whatsapp-message-queue): Practical implementation guide.
- [guides — prevent-duplicate-whatsapp-messages](https://chatrail.dev/guides/prevent-duplicate-whatsapp-messages): Practical implementation guide.
- [guides — correlate-whatsapp-reply-alert](https://chatrail.dev/guides/correlate-whatsapp-reply-alert): Practical implementation guide.
- [guides — reconnect-whatsapp-linked-device](https://chatrail.dev/guides/reconnect-whatsapp-linked-device): Practical implementation guide.
- [guides — whatsapp-sent-delivered-read](https://chatrail.dev/guides/whatsapp-sent-delivered-read): Practical implementation guide.
- [guides — verify-whatsapp-webhook-signature](https://chatrail.dev/guides/verify-whatsapp-webhook-signature): Practical implementation guide.